The use of matching lugs in connection with seating a container closure on a container has been used in various forms as is shown by U.S. Pat. Nos. 3,194,455, Castelli and 3,325,066, Allen. However, none of the prior art has addressed the problem of variations in the height of the upper lip of the opening of the closure which is known as the land, and which dimension is very difficult to maintain precisely in the molding process.